Driver tool for self-tapping inserts



June 6, 1953 F. w. BRAENDEL DRIVER TOOL FOR SELF-TAPPING INSERT VENTORATTORNEYS Z Q mm Filed Jan. 9, 195];

m 4 a I: D! 1 3 2 w W a BMW fiflfi I lug 9 M. w b 2 TL 5 I w W 2Patented June 16, 1953 r UNITED. STATES PATENT oFFicE;

2,641,94sj DRIVER, TOOL FOR SELF-,TAPPING INSERTS Felix W. Braendel,Teaneck, N. J., assignor to Groov-Pin Corporation, a corporation of NewYork Application January 9, 1951, Serial No. 205,094

7 Claims.

for the application of self-tapping screw mounting inserts into untappedbores of plastic and metal structures. 1

line comprises a tubular member ID of steel,

preferably hardened steel, transversely slotted at H at its entry endacross its external threads I2 to form cutters at the advance edges ofsuch slot for gouging the metal or plastic from the As conducive to aclear understanding of the 5 smooth generally cylindrical bore IS in thestrucinvention, it is noted that the relatively high ture S to which theinsert is to be applied, so tapping torque required for introducing aselfthat the insert will tap into the smooth bore a tapping insert ofharder metal into a bore in a thread I! which is snugly conformed tothread softer structure; such as aluminum, plastic or I2 of the insertIll for secure accjommodation'in the like, and driving it homefrequently causes thestructure S. The insert is tubular in form thedriver tool to become so tightly locked against as shown and its .boreis tapped at l5 for the the exposed end of the insert that the reversepurpose of accommodating the correspondingly torque applied to thedriver tool for removal is threaded end It of the driver tool used ininstallnot always effective to unscrew it from the inin such insert andafter removal of such tool to stalled insert, but rather moves theinsert with accommodate the screw (not shown) for which the tool forrelease and withdrawal from the the insert is to afiord a secure anchorin the soft st tu e i whi h it; was i st lled, metal or plasticstructure S in which the insert is It is accordingly among the objectsof the inaccommodated. While the insert is shown as of vention toprovide a driver tool for the above the headless variety, it may ifdesired be propurpose, which is simple, rugged and inexpensive Videdwith a head such as shown in the-embodiin constructionand which requiresnospecial skill ment illustrated in the patent above identified. ortechnique for its operation, and which in fact The driver tool Show ithe W s 0 mis employed in the same manner as any ordiprises a Shankwhich ay have a keying pp nary driver tool, but which reliably assuresits end 58 o Which may be app a suitable handle release from the insertupon starting to turn the (not shown) for operat the ooldriver tool inunscrewing direction, and affords The tOOl so presents a reaction faceI9 which such assurance regardless how tight the tool may engages theouter eXtr m y 0f the sert when have become locked to the insert in theinstallathreaded as far as it will go 1113011 aded e d tioiroperation,so that the tool may be removed S0 that during orque tra smission forinstal without the slightest tendency to loosen, much lation of the i sindicated in there less, t unscrew t tightly i t h d t, will be norotary displacement of the insert rela- I In the accompany drawings inwhich is shown t to the S a k.

one of various possible embodiments of the sev- If the threaded e d l6precluded all lost eral features of t invention, motion, not only whiledriving the insert into v Fig. 1 is a fragmentary view in longitudinal 11 but also in c wi g for removal of the cross section showing therelation of a preferred driver then Since the torque exerted in p rmformof tool to the insert and the structure in i the tappin op rati n qu ysults in which that insertis about to be installed, look ng the toolsecurely to the Outer extremity Fig 2 is a perspective view Showing t 1I of the insert, such insert may move as a unit tion of the parts in thecourse of installation of- With the ol in tool release operation and athe insert, I cordingly becomes loosened from the structure Fig 3 is aSide 1 t partly in t o in which it had been installed and backs outShowing t insert in place and t position of from such structure in therelease movement of the tool as it is about to be withdrawn, and drive?Fig. 4 is a transverse sectional View taken on ACOOTdlhg t0 the p s nt Ivention, this difliline 4 4 f Fj g 1 oulty is completely obviated byintroducing a tool The invention is more especially concerned .releasetransmission T between the operating with'a driver tool for theconvenient installation shank and the exposed face of the installed inofa self-tapping screw mounting insert of hard start, which transmissiondoes not interfere with metal intended for introduction into soft metalthe installation of the insert but afiords sufficient and plasticstructures. One preferred form of p y n commencing reverse or removalturn of such insert to which the tool has particular the driver torelease it from the-insert, so'that it applicability is that made thesubject of U. S. is readily screwed out of the insert without im- PatentNo. 2,455,885, issued December '7, 1948, to pairing the security withwhich the insert had Erich G. Theurer; The insert in its general outbeenlodged into the structure.

According tothe invention in a preferred embodiment, the driver toolrelease transmission comprises two coacting coupling members 20 and 2|which encompass the operating end of the driver tool shank. The uppercoupling member is preferably a drive disk 20 rigidly affixed to theshank and the lower Or driven coupling member is a tool release collar2! movably mounted with respect to the shank and has the thrust face l9that engages the exposed end of the insert 10. Interposed between thetwo coupling members is a low friction thrust bearing 22,,preferably aball bearing encompassing the shank and spacingthe two coupling membersas at 23.

For operating the driven or tool release'collar 2| from the driving ordrive disk 20, a set of lugs, desirably two diametrically opposed lugs24protrude downward from the face of the drivedisk 20 and two associatedlugs 25 also diametrically opposed to each other protrude upward fromthe release'collar'2 l. Lugs 24-.and25 which are preferably integralwith the respective coupling members, are of width in circumferentialdirection such,-that in theassembly there is substantial clearance at 25between the corresponding lugs of the two coupling members. Moreover,the

height of these lugs is somewhat less than the thickness of theanti-friction or ball bearing 22 so that, as shown, the free end of eachlug is maintained-somewhat spaced from the face of the opposed'couplingmember to aiford the spacing 23 above referred to.

In apreferred embodiment shown, the respective coupling members are ofcylindrical stock. The lugs 25 on the driven coupling are formed bymilling a circular trough 21 into the upper face i of the release collar2| and milling away a segment 2-8 diametrically across the mid sectionof the rim thus formed. The lugs 24 on the driving coupling 2G aresimilarly formed by milling a circulartrough 29 into one face thereofand milling away lateral segments -33 and 3| of the resultant upstandingrim. The three segments 28, '30 and 3| are of width such as to leave thedesired clearance as "at 26 between the associated driving and drivenedges 32 and 33 of lugs 24 and .25,respectively, when the parts are inthe position shown in Fig. 3. Accordingly the two coupling members ofthe release transmission in effect constitute a cylindrical casing ofwhich the coacting opposed driving and driven lugs '24 and 25 form themedian wall portion for accommodating the ball bearing 22 therein.

The driven or'release coupling member 2| is preferably mounted inposition by a flexible hanger or connection to the driving coupling'member or drive disk 2%. This hangerconnection members :headed at 35,or if desired ordinary screws may serve for anchorage of these springs.For convenience and simplicity of construction,

'the release transmission T may be'mounte'd on a rod-extension of theshank, which is desirably a separate rod R securely anchored in 3.correspondingsocket 31 in the lower end of the shank ll.

The drive .disk 20 in such embodiment may be securely threaded upon therod, firmly to engage the end 38 of the main shank for rigidoonnectionthereto. The release collar 2| has a bore -39 therethrough which hasslightclearance about the rod R and is-free'to move thereon.The'extremity of the rod as above indicated, protrudes -R. and thenbrought into registry with the untapped opening [3 in the structure Sinto which it is to be introduced and applied, desirably in a suitablejig while turning the shank ll of the driver tool, in which operationthe thrust disk lugs 24 will firstengage at each driving edge 32 thecorresponding driven edge 33 of lugs 25 on release collar 2|, as shownin Fig. 2, and the insert will tap its-way into the structure by torquedirectly transmitted from the shank ll, thrust being at the same timeapplied against the insert through face l9 of the release collar 2 I.The release transmission T does not interfere with this operation, sincerelease collar 21 is driven from 'lugs'2kl' of the thrust disk to turnas a unit'with the shank as the'insert is screwed into place.

When the insert has beenthreaded home, the

locked to the exposed face of the insert [0. "In

now turning the driver tool in reverse direction for the purpose ofremoving it, it is clear that the drive disk 23 will move with littlefriction upon the ball'bearing 22 so-tha-t its lugs 24 will move throughthe gap 25130 engage the rear edge 32' of lugs 24 with edge 33' of lugs25. In this movement, the shank ll and'with it the rod Rare turnedthrough a small fraction of a revolution in unscrewing direction so thatthe entir tool including the thrust disk20 and release collar 2- arelifted by a small fraction of an inch, whereby collar 2| disengages theexposed end of the installed insert ['3 without imposing any looseningstrain whatsoever upon such insert.

Thus any lock of the release collar to the insert is broken andthereupon the tool may bethreaded out of the insert withease.Accordingly, regardless how secure becomes thelock between the tool andrugged construction and that the manipulations in operating the same-forinstalling a selftapping insert-and for'thereupon removing the tooltherefrom'arethe same as if the-tool .were

devoid of any release instrumentality.

As many'changescould be made-in the above construction and manyapparently Widely different embodiments of this invention could be madewithout departing from the scope of the'claims, it is intended :that allmatter contained in the above description'or shown in the accompanyingdrawings shall be interpretedas illustrative and not-in a limitingsense.

Having thus described my invention what I claim as new and 'desire tosecure by LettersPatent of the United States is:

1. A quick release driver tool for the application of a self-tappingscrewmounting insertinto an untapped'bore'in'nietalorthe like. said toolcomprising a shank, a tool release collar encomthrust bearingencompassing the shank, :said

shank having means to press said thrust bearing against said toolrelease collar, and means for limiting the rotary movement of therelease collar relative to the shank.

2.. A quick release driver tool for the application of a self-tappingscrew mounting insert to an untapped bore in metal or the like, saidtool comprising a shank, a tool release collar movably encompassing saidshank, said shank having a threaded end protruding beyond said collarfor releasable mount of an insert thereon, and for abutment of saidinsert against said collar, a drive disk rigid with said shank andencompassing said shank, a low-friction thrust bearing encompassing saidshank and interposed between said drive disk and said release collarvand spacing them apart, means loosely attaching said release collar tosaid drive disk to permit relative movement therebetween, and stop meanson said drive disk and said release collar cozzcting to limit therelative rotary movement therebetween.

3. A quick release driver tool for the application of a self-tappingscrew mounting insert into an untapped cylindrical bore of metal or thelike, said tool comprising a shank, a rod secured in the end of saidshank and threaded at its free end for releasable screw mount of aninsert, a drive disk about the rod and rigidly aflixed thereto, a toolrelease collar about the rod, a low friction thrust bearing about therod and interposed and maintaining a distance between said drive diskand said tool release collar, yielding means attaching said releasecollar to said drive disk to permit relative movement therebetween andcoacting stop means on said disk and collar respectively to limit therelative rotary movement thereof.

4. A quick-release driver tool for the application of a self-tappingscrew mounting insert to an untapped cylindrical bore in metal or thelike, said tool comprising an operating shank having a rod threaded intothe extremity thereof and protruding therebeyond, a drive disk threadedupon said rod and abutting the end of said shank, a tool release collarencompassing said rod, a low friction thrust bearing encompassing saidrod and interposed between said drive disk and said release collar andmaintaining said elements in spaced relation, hanger means yieldablyattaching the thrust release collar to the drive disk and coacting stopmeans rigid'respectively with the drive disk and the release collar tolimit the relative rotary displacement therebetween, the extremity ofthe threaded rod protruding beyond the release collar and serving forreleasable mount of a threaded insert to be attached.

5. A quick-release driver tool for the application of a self-tappingscrew mounting insert to an untapped cylindrical bore of metal or thelike, said tool comprising an operating shank, a threaded rod mounted inand protruding from the forward end thereof, a tool release transmissionabout said rod and in thrust relation to said shank, said rod protrudingbeyond said transmission for releasable mount thereon of the insert tobe applied, said transmission comprising a drive disk rigid with theshank and a loosely mounted release collar about the rod and affording athrust face to engage such insert, a low friction thrust bearinginterposed between said drive disk and said release collar andmaintaining the same in spaced relation, said drive disk having lugsrigid therewith extending toward the release collar and the latterhaving lugs rigid therewith extending toward the drive disk, said lugson the respective transmission elements being spaced peripherally fromeach other to transmit torque from the drive disk to the release collarin the application of an insert and in the reverse rotation of theshank, after taking up the clearance between the drive disk and therelease block to transmit torque to the latter for removal of the toolfrom the installed insert.

6. A quick release driver tool for the application of a self-tappingscrew mounting insert to I an untapped cylindrical bore of metal or thelike,

said tool comprising a shank, a threaded rod protruding beyond saidshank, a tool release transmission comprising a driving coupling memberrigid with the shank and a loosely mounted driven coupling member,flexible attachment means se cured at the peripheries of the respectivecoupling members to maintain the loosely mounted driven coupling memberassembled to the rest of the structure, said coupling members eachhaving drive lugs rigid therewith and protruding therefrom, those ofeach coupling member being interposed between those of the other withclearance therebetween to permit limited rotary displacement of thedriven coupling member, a ball bearing interposed between saidtransmission members and spacing them slightly apart, said ball bearingencompassing the rod and being encompassed by the lugs of the twocoupling members, the threaded rod extending beyond the releasetransmission for mounting an insert, said driven coupling memberpresenting a thrust face for engagement with such threaded insert.

7. The combination recited in claim 6 in which the flexible attachmentmeans comprises coil springs affixed at their ends to mounting pegsprotruding from the respective coupling members.

FELIX W. BRAENDEL.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 702,934 Errington June 24, 1902 1,125,186 Schneider 1 Jan. 19,1915 1,308,490 Funk July 1, 1919 1,664,442 Weil et a1. Apr. 3, 19282,160,150 Jimerson et a1. May 30, 1939 2,450,185 Craven Sept. 28, 1948

